http://www.mindat.org/msgboard-79.html Sat, 25 May 2013 05:17:26 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,79,279153,279153#msg-279153 http://www.mindat.org/forum.php?read,79,279153,279153#msg-279153 Best Minerals and here for Tourmaline group minerals, here for Chromium-dravite, here for Chromo-alumino-povondraite, here for Dravite, here for Elbaite, Afghanistan to Nigeria, here for Elbaite, Pakistan to Zambia here for Feruvite, here for Fluor Buergerite here for Fluor-dravite, here for Fluor-elbaite, here for Fluor-feruvite, here for Fluor-liddicoatite, here for Fluor-schorl, here for Foitite, here for Liddicoatite, here for Luinaite-(OH), here for Magnesiofoitite, here for Olenite, here for Oxy-dravite, here for Oxy-rossmanite, here for Oxy-schorl, here for Povondraite, here for Rossmanite, here for Schorl, here for Tsilaisite and here for Vanadium-dravite. Click here for Best Minerals T and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.



Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Magnesiofoitite: Trigonal
(□,Na)(Mg₂Al)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)

Magnesiofoitite in quartz 4.3cm wide, Pingwu Co., Sichuan Province, China	© Jiangbin

There are currently 14 localities listed on Mindat for magnesiofoitite (2013). The type locality is Kyonosawa, Mitomi-mura, Yamanashi prefecture, Chubu region, Honshu Island, Japan.


Magnesiofoitite
China
Sichuan Province, Mianyang Prefecture, Pingwu Co., Mt Xuebaoding, Huya township, Huya W-Sn-Be deposit (Pingwu beryl mine)

Magnesiofoitite & quartz 6.1cm tall	© Jiangbin

Magnesiofoitite & quartz, 6.2cm tall	© Jiangbin

Magnesiofoitite & quartz 6.4cm tall	© Jiangbin

Magnesiofoitite
Japan
Honshu Island, Chubu region, Yamanashi prefecture, Mitomi-mura, Kyonosawa

Magnesiofoitite FOV 5mm	© Thomas Witzke

This is the type locality for the magnesiofoitite.


Magnesiofoitite
Russia
Urals Region, Middle Urals, Sverdlovskaya Oblast', Ekaterinburg (Sverdlovsk), Berezovskii (Berezovskii Zavod), Berezovskoe Au Deposit (Berezovsk Mines), Pyshminskoe (Staro-Pyshminskoye) deposit

Magnesiofoitite 4cm wide	© Pavel M. Kartashov

Magnesiofoitite
USA
California, Inyo Co., White Mts, Laws, White Mountain, Champion Mine (White Mountain Mine)

Hairs of magnesiofoitite, woodhouseite & quartz FOV 1cm	© Wm. Wise (2006)

Click here to view Best Minerals and here for Tourmaline group minerals, here for Chromium-dravite, here for Chromo-alumino-povondraite, here for Dravite, here for Elbaite, Afghanistan to Nigeria, here for Elbaite, Pakistan to Zambia here for Feruvite, here for Fluor Buergerite here for Fluor-dravite, here for Fluor-elbaite, here for Fluor-feruvite, here for Fluor-liddicoatite, here for Fluor-schorl, here for Foitite, here for Liddicoatite, here for Luinaite-(OH), here for Magnesiofoitite, here for Olenite, here for Oxy-dravite, here for Oxy-rossmanite, here for Oxy-schorl, here for Povondraite, here for Rossmanite, here for Schorl, here for Tsilaisite and here for Vanadium-dravite. Click here for Best Minerals T and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.

[First draft of Best Minerals magnesiofoitite completed in May 2013]]]> Rock Currier Best Minerals M Fri, 14 Dec 2012 11:47:32 +0000 http://www.mindat.org/forum.php?read,79,254137,276495#msg-276495 http://www.mindat.org/forum.php?read,79,254137,276495#msg-276495 Ralph Bottrill Best Minerals M Sun, 18 Nov 2012 13:08:20 +0000 http://www.mindat.org/forum.php?read,79,254137,276404#msg-276404 http://www.mindat.org/forum.php?read,79,254137,276404#msg-276404
A specimen from the Zagi Mts, Pakistan that you may be able to use.

[www.mindat.org]]]> Craig Mercer Best Minerals M Sat, 17 Nov 2012 05:00:36 +0000 http://www.mindat.org/forum.php?read,79,254137,254225#msg-254225 http://www.mindat.org/forum.php?read,79,254137,254225#msg-254225 James Christopher Best Minerals M Sun, 04 Mar 2012 05:46:08 +0000 http://www.mindat.org/forum.php?read,79,254137,254223#msg-254223 http://www.mindat.org/forum.php?read,79,254137,254223#msg-254223 You should ask Frank Roberts for pics of his Burnet County Monazites.
-Dean Allum]]> Dean Allum Best Minerals M Sun, 04 Mar 2012 04:35:43 +0000 http://www.mindat.org/forum.php?read,79,254137,254203#msg-254203 http://www.mindat.org/forum.php?read,79,254137,254203#msg-254203 Pavel Kartashov Best Minerals M Sat, 03 Mar 2012 23:59:03 +0000 http://www.mindat.org/forum.php?read,79,254137,254194#msg-254194 http://www.mindat.org/forum.php?read,79,254137,254194#msg-254194 Rock Currier Best Minerals M Sat, 03 Mar 2012 22:54:17 +0000 http://www.mindat.org/forum.php?read,79,254137,254137#msg-254137 http://www.mindat.org/forum.php?read,79,254137,254137#msg-254137 This Article is Under Construction

4cm x 3cm x 2.5cm.	© M.Willoughby '07

Click here to view Best Minerals M , and here for Best Minerals A to Z and here for Fast Navigation for finished Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities? After each set of pictures there should be some descriptive text. If none appears it means that we need someone to tell us about the specimens from that locality and something about the geology of the occurrence.

The name monazite is used here for all members of the monazite group. "Monazite", without a elemental suffix, was once the accepted name for all material in this group, regardless of the REE-bearing components' relative abundance. The suffixes were added when the naming convention for all REE-bearing members was devised and implemented.
Most "monazite" is monazite-(Ce), the La-, Nd-, Sm- and Gd-dominant members are all very rare.
Monazite often contains small amounts of U and/or Th, making it radioactive.

Australia
Torrington, Clive Co., New South Wales, Australia

© S.M. Whittemore

[www.mindat.org]

Kings Bluff mine, Olary, Olary Province, South Australia, Australia

4cm x 3cm x 2.5cm.	© M.Willoughby '07

Austria
Lower serpentinite quarry, Zwettler Leiten, Felling, Gföhl, Waldviertel, Lower Austria, Austria


Königsalm, Senftenberg, Waldviertel, Lower Austria, Austria
size
Hopffeldboden, Hopffeld area, Obersulzbach valley, Hohe Tauern, Salzburg, Austria
size
Lohning quarry (Lohninger quarry), Hüttwinkl valley, Rauris valley, Hohe Tauern, Salzburg, Austria
size
Diabase quarry, Biberg (Bieberg), Saalfelden, Salzburg, Austria
size
Oberschrammach glacier, Schrammacher, Zamser Grund (Zams valley), Ziller valley, North Tyrol, Tyrol, Austria
size

Bolivia
Llallagua, Rafael Bustillo Province (Bustillos Province), Potosí Department, Bolivia
size

Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province (Bustillos Province), Potosí Department, Bolivia

© Joseph A. Freilich LLC

http://www.mindat.org/photo-169369.html
75 x 55 x 35 mm. crystals to 9 mm. and twinned. Crystals exhibit color change.

©

http://www.mindat.org/photo-303967.html

©

http://www.mindat.org/photo-303969.html


Brazil
João Torres Mine, Muqui, Espírito Santo, Brazil

© Rob Lavinsky

http://www.mindat.org/photo-169954.html
4.7 x 4.4 x 1.4 cm.

Buenópolis, Minas Gerais, Brazil

© KhyberMinerals.com

http://www.mindat.org/photo-141881.html
2.2x1.4x 1.3 cm

São João da Chapada, Diamantina, Jequitinhonha valley, Minas Gerais, Brazil

© R Bottrill

http://www.mindat.org/photo-453378.html



Canada
Ojaipee Mine, Doley Lake, Conger Township, Parry Sound District, Ontario, Canada


Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, Rouville RCM, Montérégie, Québec, Canada


Czech Republic
U obrázku quarry, Písek, South Bohemia Region, Bohemia (Böhmen; Boehmen), Czech Republic

Dolní Bory, Žďár nad Sázavou, Vysočina Region, Moravia (Mähren; Maehren), Czech Republic


France
Trimouns Talc Mine, Luzenac, Ariège, Midi-Pyrénées, France

Plan-du-Lac, St Christophe-en-Oisans, Bourg d'Oisans, Isère, Rhône-Alpes, France


Trouée des Fées, Les Deux Alpes, Isère, Rhône-Alpes, France

La Lauzière massif, Savoie, Rhône-Alpes, France

L'Homme de Beurre, La Lauzière massif, Savoie, Rhône-Alpes, France

La Madeleine pass, La Lauzière massif, Savoie, Rhône-Alpes, France

La Léchère (Notre Dame de Briançon), Tarentaise valley, Savoie, Rhône-Alpes, France

Germany
Laach lake volcanic complex, Eifel, Rhineland-Palatinate, Germany

Agpat (Appat), Tunugdliarfik Firth (Eriksfjord), Ilimaussaq complex, Narsaq, Kitaa (West Greenland) Province, Greenland

Brenva Glacier, Veny Valley, Monte Bianco Massif (Mont Blanc Massif), Courmayeur, Aosta Valley, Italy
Miage Glacier, Veny Valley, Monte Bianco Massif (Mont Blanc Massif), Courmayeur, Aosta Valley, Italy


Ossola Valley, Verbano-Cusio-Ossola Province, Piedmont, Italy

xls mm3x3 FOV cm 1	©

[www.mindat.org]
Beura Quarries, Beura-Cardezza, Ossola Valley, Verbano-Cusio-Ossola Province, Piedmont, Italy


Vizze pass (Pfitsch pass), San Giacomo, Vizze Valley (Pfitsch Valley), Bolzano Province (South Tyrol), Trentino-Alto Adige, Italy
Croda Alta (Grawandkofel), Vizze pass (Pfitsch pass), San Giacomo, Vizze Valley (Pfitsch Valley), Bolzano Province (South Tyrol), Trentino-Alto Adige, Italy

Madagascar
Madiaomby pegmatite, Anjozorobe District, Ankazobe Pegmatite Field, Analamanga Region, Antananarivo Province, Madagascar
Ambatofotsikely pegmatite, Fidirana Commune, Betafo District, Vakinankaratra Region, Antananarivo Province, Madagascar
[www.mindat.org]
[www.mindat.org]

Ankazobe Pegmatite Field, Analamanga Region, Antananarivo Province, Madagascar
[www.mindat.org] Monazite, complete crystal, 22 x 17 x 8 mm., Ankazobe, Madagascar. Somewhat radioactive (~75 microrems/hr.). A Dave Shannon specimen, purchased in 2000, the label said collected in 1925. K. Nash

Narestø Feldspar Quarry, Flosta Island, Arendal, Aust-Agder, Norway
[www.mindat.org]

Landsverk 1 Feldspar Quarry (Jokeli), Landsverk, Evje og Hornnes, Aust-Agder, Norway
[www.mindat.org]

Iveland, Aust-Agder, Norway

Frøyså, Iveland, Aust-Agder, Norway

Rostadheia, Mølland, Iveland, Aust-Agder, Norway

Moss, Østfold, Norway

Pakistan
Zagi Mountain (Zegi Mountain; "Shinwaro"), Hameed Abad Kafoor Dheri, Peshawar, Khyber Pakhtunkhwa (North-West Frontier Province), Pakistan

FOV 20mm x 20mm.	© C.Mercer

Ytterlida pegmatite, Överlida, Svenljunga, Västergötland, Sweden

Rutströmsselet, Vassijaure, Lappland, Sweden
[www.mindat.org]

A 5 mm big Monazite	© AÖ

Råneå, Norrbotten, Sweden

15x20x30 mm	© AÖ

Normally the crystals are found in schorl from the Sörhällan quarry.

FOV 40mm x 40mm.	© AÖ

Cavradi gorge, Curnera Valley, Tujetsch (Tavetsch), Vorderrhein Valley, Grischun (Grisons; Graubünden), Switzerland

Croft Gothal Mine, St Hilary, Mount's Bay District, Cornwall, England, UK

Croft Gothal Mine, St Hilary, Mount's Bay District, Cornwall, England, UK

USA
Cross Hill, Juniper Flats, Neuvo, Riverside Co., California, USA

© crocoite.com

http://www.mindat.org/photo-433007.html

McGuire pegmatite (Lone Lode; Lonesome pegmatite), Park Co., Colorado, USA
Slocum Prospect, East Hampton, Middlesex Co., Connecticut, USA

© 2001 John H. Betts

http://www.mindat.org/photo-1191.html

Andrews Quarry (old Hale Quarry; Grandfather Andrews Quarry), Portland, Middlesex Co., Connecticut, USA



Swamp #1 quarry, Topsham, Sagadahoc Co., Maine, USA
[www.mindat.org]


Bald Mountain, Ossipee, Carroll Co., New Hampshire, USA
[www.mindat.org]

Yates Brooks Farm, Lattimore, Cleveland Co., North Carolina, USA

Milford, San Francisco District (Frisco District), San Francisco Mts, Beaver Co., Utah, USA
[www.mindat.org]


Katydid Mine (Rogers Publishing Company Mine), Wilkerson Pass Area, Park Co., Colorado, USA]]> Ralph Bottrill Best Minerals M Sat, 03 Mar 2012 14:24:19 +0000 http://www.mindat.org/forum.php?read,79,130896,249442#msg-249442 http://www.mindat.org/forum.php?read,79,130896,249442#msg-249442 That's a very nice millerite and should be in the best millerites, but unless you upload it to our database formally and not just as an attachment to a thread post like you did here, it won't be included.]]> Rock Currier Best Minerals M Tue, 17 Jan 2012 06:58:50 +0000 http://www.mindat.org/forum.php?read,79,130896,249343#msg-249343 http://www.mindat.org/forum.php?read,79,130896,249343#msg-249343 ophiolites scattered in cretaceous sedimentary layers.]]> Andrea Sansoni Best Minerals M Mon, 16 Jan 2012 16:01:15 +0000 http://www.mindat.org/forum.php?read,79,130896,249330#msg-249330 http://www.mindat.org/forum.php?read,79,130896,249330#msg-249330 Could you add it to the database?

Cheers,

Harjo]]> Harjo Neutkens Best Minerals M Mon, 16 Jan 2012 13:43:28 +0000 http://www.mindat.org/forum.php?read,79,130896,249325#msg-249325 http://www.mindat.org/forum.php?read,79,130896,249325#msg-249325 BOB HARMAN Best Minerals M Mon, 16 Jan 2012 12:33:27 +0000 http://www.mindat.org/forum.php?read,79,130896,249315#msg-249315 http://www.mindat.org/forum.php?read,79,130896,249315#msg-249315 Harjo Neutkens Best Minerals M Mon, 16 Jan 2012 08:58:30 +0000 http://www.mindat.org/forum.php?read,79,130896,207551#msg-207551 http://www.mindat.org/forum.php?read,79,130896,207551#msg-207551 Harjo Neutkens Best Minerals M Sun, 26 Dec 2010 22:03:55 +0000 http://www.mindat.org/forum.php?read,79,130896,207538#msg-207538 http://www.mindat.org/forum.php?read,79,130896,207538#msg-207538

© Maggie Wilson

just uploaded - not the best photo on the planet, but a sample of the locality

Knut Eldjarn Wrote:
-------------------------------------------------------
> Harjo,
>
> You absolutely need to describe the millerites
> from the Saranay locality in the Urals. They are
> some of the best in the world. From a
> mineralogical point of view, the large, bronze
> cleavages of millerite from the Marbridge mine in
> Canada are also quite interesting and showy for
> what they are - but you probably have to have
> insight into ore mineralogy to really appreciate
> those !).
>
> Knut]]> Maggie Wilson Best Minerals M Sun, 26 Dec 2010 18:51:22 +0000 http://www.mindat.org/forum.php?read,79,201847,204025#msg-204025 http://www.mindat.org/forum.php?read,79,201847,204025#msg-204025 I have made a few tweaks to the formatting of your suggested addition to the magnetite article. Click on the edit button at the bottom of your post and you can see the code adjustments that I made. Note that in the second image, the code string I changed the left to center which gives it a little space between the images. I also adjusted the pixel size a little to line the pictures up. It looks good now.

You are a moderator in the best minerals group, why don't you go ahead and copy the whole thing into the magnetite article in the appropriate place?

What do you want to work on next? or perhaps you are already working on something.]]> Rock Currier Best Minerals M Mon, 29 Nov 2010 19:21:10 +0000 http://www.mindat.org/forum.php?read,79,201847,203985#msg-203985 http://www.mindat.org/forum.php?read,79,201847,203985#msg-203985
Please see below.

Olav


Magnetite
Norway
Telemark, Porsgrunn, Mørje, Auen( Blue Pearl) Quarry

Magnetite 2,5cm	©

Hematite after Magnetite. 6,2 cm wide	© Ingulv Burvald

Auen is one of the many larvikitie quarries in this area. Larvikite is quarried as a dimension stone and is widely used as countertops and claddings. The commercial grade larvikite consist predominantly of blue or black schillerizing feldspar.
The larvikite was formed as igneous plutons during Permian (+/- 300mill years ago) rifting in the Oslo graben in southeastern Norway. These igneous plutons are host to numerous alkaline pegmatites carrying many rare minerals.

The magnetite at Auen was found in one of these pegmatites in 1996. The actual pegmatite was severly altered, with a clay mineral, albite covered microcline and magnetite as main minerals. Small zircon, molybdenite sheets and a yellow, transparent mineral was present as accessory minerals. Most of the magnetite was partly altered to hematite
The magnetite crystals reached almost 10 cm across and often had quite complex crystal shapes. The best specimen I found was a 15cm wide cabinet specimen consisting of three intergrown magnetite crystals. This specimen is now on loan to Agder Naturmuseum in Kristiansand. The magnetite was abundant in this material, and several truck loads of material were available just after the pegmatite was exposed, and magnetite could still be found in the quarry a few years after the initial exposure of material.]]> Olav Revheim Best Minerals M Mon, 29 Nov 2010 15:48:43 +0000 http://www.mindat.org/forum.php?read,79,201847,201847#msg-201847 http://www.mindat.org/forum.php?read,79,201847,201847#msg-201847 Best Minerals M, click here to view and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?



Magnetite
Fe²⁺Fe³⁺2O₄ Isometric

Magnetite on Albite, 5cm tall	© 2003 John H. Betts

Magnetite on Albite, Cerro Huañaquino, Potosí Department, Bolivia 5cm tall
The name magnetite is apparently derived from the locality Magnesia, which borders on Macedonia. The ancient writers, Pliny and Nickander attribute the name to a person? named Magnes who on taking his herds to pasture found that the nails of his shoes and the iron ferrule of his staff stuck to the ground.

So far Mindat lists more than 9700 localities for magnetite and undoubtedly there are many more. Magnetite is one of the most abundant and commonly found oxides and is found under diverse geological conditions and sometimes in sufficient quantity to comprise an ore of iron. Magnetite is commonly found as grains in igneous rocks but most abundantly in the ferromagnesian types and at times as large segregated masses. Often these contain a lot of titanium in their composition due mostly to illmenite. Magnetite forms in the same conditions which form hematite and is usually if not always formed under conditions of high temperature. It it is found in the fusion crusts of meteorites and as dendritic forms in the mica of many localities and may be of secondary origin. It is also noted as a furnace product in slags and in sintered hematite ores. Brick, vitreous clay ware, and porcelain acquire a permanent magnetization parallel to the earths's magnetic field if magnetite crystals form during the firing. The largest deposits of magnetite are found in lens shaped masses in northern Sweden in Archaean rocks

A strong indicator that you may have magnetite is to see if it is attracted by a magnet and by checking its streak which is black. Maghemite, another strongly magnetic iron oxide, is brown to bluish black and can easily be confused with magnetite. However, unlike magnetite, it transmits light in thin splinters and has a brown streak. Hematite for which Magnetite is occasionally mistaken has a dark red streak and is not attracted by a magnet. Heating magnetite to 550 degrees C however alters the mineral to hematite and causes loss of its magnetic property. Magnetite alters to limonite and to hematite. Magnetite pseudomorphs after pyrite, chlorite minerals, anatase, talc, dolomite, chalcopyrite, siderite, and serpentine are known. Presumably all of these may be found not completely altered and containing the originative mineral and magnetite as well. So if you get a reaction to a magnet from a mineral, it may also not be a pure mineral, but partly magnetite. At some few localities, magnetite possesses polarity and this magnetite is given the variety name of lodestone. This means that the magnetite will act as a natural magnet. This natural magnetism can sometimes be enhanced by placing it in a strong magnetic field.

Magnetite crystals are most commonly found as octahedrons, but is also found in dodecahedrons with striated faces and more rarely as cubes. Sometimes octahedral forms of magnetite are altered to hematite and this is common enough that they are given the varietal name of martite (hematite, var. martite). Sometimes pure masses of twinned magnetite are found and when broken along its parting planes forms crystals that are sometimes mistaken for crystals of magnetite but are in reality just parting forms of twinned magnetite. The magnetite from Port Henry, New York example these. The cleavage of untwinned magnetite is not distinct.

The literature on magnetite and hematite is extensive and not something we want to go into here. Much of what is above was taken from Dana's/Ford text and Dana's system 7th edition, V1, P698-705 which has a nice summary of information about magnetite.

Historically, the most sought after crystals by collectors were perhaps those from Switzerland. Recently however the new find of good octahedral magnetites from Cerro Huañaquino, Bolivia and especially the new brilliant cubic magnetites from Balmat, New York, USA have displaced the Swiss specimens as the most desired. However, you can look at good examples of all of these and more in the picture gallery below and make up your own mind.
[Rock Currier 2010]


Magnetite
Afghanistan
Nangarhar Province (Ningarhar Province), Khogyani, Marki Khel
Nangarhar Province (Ningarhar Province), Speen Ghar

Magnetite3.7cm tall	© Dan Weinrich

Magnetite 2.1cm tall	© Rob Lavinsky

The one on the left above is from Marki Khel, and the one on the right from Speen Ghar. It would appear that both of these specimens are very likely from the same locality and at the very least we hope someone can help sort out what these two locality names represent when it comes to the specimens from them.


Magnetite?!!!
Argentina
Mendoza, Altiplano de Payún Matru, Payún volcano

Magnetite?!!! 4.5cm wide	© Rockpick Legend Co.

Magnetite?!!! 10.3cm tall	© Fabre

Specimens like this from Payún volcano are usually labeled Hematite after Magnetite and many more and much better examples are shown under Hematite in the Mindat Gallery and the Best Minerals Hematite article. It is possible that these specimens have still retained their magnetic character and that is why they are currently labeled magnetite. It is also possible, and perhaps even likely that these specimens have been mislabeled and are really now Hematite. Many collectors and some dealers really don't pay much attention to the accuracy of the labels they receive with their specimens or generate themselves and don't take the time to run even the simplest of tests on their specimens to determine if perhaps the labels may be in error. In fact they don't even know how. As time passes and you learn more and gain more experience you will see more and more errors on labels and will learn to look specimen labels with a more critical and analytical eye. We need more of this kind of person here on mindat to help clean up the mistakes and errors that exist here on Mindat.
"Although these specimens are usually labelled "Payun" or "Payun Matru" volcano, this is actually in a rather extensive volcanic field with dozens of vents, and exactly which fissures these crystals came from has understandably not been revealed by the prospectors who dig them, and there are at least two localities for them in this area, so "Payun Matru region" or just "Altiplano de Payun Matru" might be a more honest locality designation, leaving off the volcano name. As is obvious from the crystal habits, these started out as magnetite, although the majority have oxidised to hematite and should now be labelled "hematite pseudomorphs after magnetite". A minority are still magnetite, or only partially replaced. Magnetite and hematite crystals, often skeletal, deposited from the gas phase in volcanic fumaroles by hydrolysis of iron chloride vapour are fairly common in high-temperature volcanic fumaroles worldwide, but these argentine examples are by far the largest and finest fumarolic magnetites known." - Alfredo Petrov, 2010.


Magnetite
Australia
Northern Territory, Harts Ranges (Hartz Ranges), Mud Tank

Magnetite 3cm wide	© JSS

This is a popular collecting spot, mostly for large zircon crystals, in a carbonatite. It was being mined for Vermiculite recntly, with collectors allowed to fossick on the dumps still. The magnetite crystals can be large, but are seldom completely intact.


Magnetite
Australia
Queensland, Biggenden Shire, Biggenden Mine (Mount Biggenden Mine; Biggenden Gold And Bismuth Mine; Mount Biggenden Bismuth Mine; Mount Biggenden Magnetite Mine; Biggenden Quarry)

Magnetite 9cm wide	© G. van der Veldt

This site was a large magnetite mine, in a skarn deposit. It was a popular spot for collecting until the mine closed some (20?) yrs ago, and specimens are rarely seen now.


Magnetite
Australia
South Australia, Flinders Ranges, North Flinders Ranges, Arkaroola area, Sitting Bull area

Magnetite 5.4cm wide	© Rob Lavinsky

A popular collecting area with various small iron, copper, fluorite and uranium deposits related to granite intrusions, but good specimens are rarely seen.


Magnetite
Australia
Tasmania, Hampshire district, Kara Mines, Kara #1 Pit

Magnetite, Andradite etc 15cm wide	© R. Bottrill 2006

An operating open-cut mine, located 40 km south of Burnie in northwestern Tasmania, producing magnetite and minor scheelite. It is the only presently operating mine in a series of related skarn deposits associated with Devonian granites intruding Ordovician limestones. The pit contains a zoned magnetite-andradite-hedenbergite-vesuvianite-epidote skarn, which contains minor scheelite and molybdenite and calcite veins with various Cu, Pb, As, Zn, Bi sulphides, fluorite and some Be minerals. Famous for excellent andradite specimens and many other interesting minerals. Magnetite is very common, often in well formed dodecahedral crystals, to about 5cm, but are typically a little dull in lustre. They may be coated in other crystallised minerals, including bavenite, fluorite, calcite, andradite, epidote, tremolite and helvite-danalite.
[Ralph Bottrill 2010]


Magnetite
Austria
Salzburg, Hohe Tauern Mts, Stubach valley, Totenkopf Mt. (incl. Lower Riffl glacier)

Magnetite & Actinolite ~9cm wide	©

Magnetite
Austria
Tyrol, North Tyrol, Ziller valley, Schlegeis valley (Schlegeisgrund), Furtschaglkar

Magnetite 16.5cm wide	©

Magnetite
Azerbaijan
Daşkəsən (Daskasan; Dashkyasan) District, Dashkesan, Dashkesan (Dashkezan) Co-Fe deposit

Magnetite 8cm tall	© 2001 John H. Betts

Magnetite 10cm center	© 2001 John H. Betts

Magnetite & Calcite 5.3cm wide	© Fabre Minerals

Magnetite & Calcite 11.9cm wide	© Rob Lavinsky

Magnetite 10cm tall	© Terry Burtzlaff

Magnetite 5cm tall	© Dan & Diana Weinrich Minerals

Magnetite & Fluorapatite 6.0cm	© Weinrich Minerals

Magnetite 12cm wide	© Dan Weinrich

Magnetite
Bolivia
Potosí Department, Cerro Huañaquino

Magnetite 3.3cm wide	© Rob Lavinsky

Magnetite 6cm wide	© Rob Lavinsky

Magnetite 5.5cm tall	© Rob Lavinsky

Magnetite 12.5cm tall	© Rob Lavinsky

Magnetite 5cm tall	© Rob Lavinsky

Magnetite 6.3cm wide	© Rob Lavinsky

Magnetite 8.6cm wide	© Rob Lavinsky

Magnetite 8.4cm wide	© Rob Lavinsky

Magnetite 4.1cm wide	© JSS

Magnetite 12.3cm wide	© Rob Lavinsky

Magnetite 6cm wide	© 2003 John H. Betts

Magnetite 5cm wide	© www.redcrystalshop.com

Magnetite 10.4cm tall	© Rob Lavinsky

Magnetite 13.1cm wide	© Rob Lavinsky

As you head north out of Potosi, the main highway for a distance passes by Cerro Huañaquino. If you look up at that point you can see little prospects scratched on the side of the mountain a few hundred feet up, and this is the locality that has produced all the recent specimens of Magnetite from Bolivia. Several thousand of them have been produced and sold to the collector market. Some of the specimens are surprisingly good and may rank among the best Magnetites found anywhere. On many specimens the magnetite crystals are growing on tiny crystals of albite.


Magnetite
Brazil
Minas Gerais, Jequitinhonha valley, Diamantina\

Magnetite 4.2cm wide	© Rob Lavinsky

Magnetite 4.8cm wide	© Rob Lavinsky

Magnetite
Canada
Nova Scotia, Annapolis Co., Hampton

Magnetite 3.5cm wide	© Maggie Wilson

John Sinkankas notes in his Mineralogy that small, beautifully crystallized magnetite crystals occur in the Triassic trap rocks of Kings and Annapolis counties.


Magnetite
Canada
Nova Scotia, Kings Co., Bay of Fundy, Amethyst Cove (Captain Kidd's Cove)

Magnetite 3.1cm wide	© Maggie Wilson

Magnetite
Canada
Ontario, Hastings Co., Bancroft District, Faraday Township

Magnetite ~6cm wide	©

Magnetite ~5cm tall.	© Danny Jones

John Sinkankas notes in his Mineralogy that a single crystal from this locality weighed in at more then 400 pounds.


Magnetite
Chile
Antofagasta Region, El Laco

Magnetite 12.9cm wide	© Rob Lavinsky

Magnetite
Cuba
Oriente Province, Firmeza District, Juragua Iron Co. Mines

Magnetite 4.5cm tall	©

Magnetite
Czech Republic
Bohemia (Böhmen; Boehmen), Ústí Region, Krušné Hory Mts (Erzgebirge), Klášterec nad Ohří, Měděnec (Kupferberg)

Magnetite 6.5cm wide	© Barry Flannery

Magnetite
France
Midi-Pyrénées, Aveyron, Decazeville, Firmi, Puy de Wolf (Puech de Voll)

Magnetite on serpentine 8cm wide	© Patrice Cmolik

Magnetite
Germany
Baden-Württemberg, Odenwald, Eberbach, Katzenbuckel Mt., Michelsberg Quarry

Magnetite 25cm wide	© Volker Betz

The Magnetite (Titanomagnetite) from Katzenbuckel are crystals up to 3cm but most of the crystals found were only a few mm. At this location the magnetite crystals are frequently oxidized to Maghemite. They are still magnetic, but the streak changes from black to brown. If etched with cold 30 % HCl this pseudomorphed crystals give a white residue of Leukoxene ( Anatase) while with the real Magnetite the black Ilmenite inclusions remains. The locality is of the European Province with unusual peralkaline dyke rocks. This location was first metioned by Leonhard in 1822 for Nepheline and is located about 35 km E of Heidelberg. With a very long list of papers until today. A milestone of petrography/ petrology research ( Rosenbusch). The quarries were operated from about 1900 to 1974, the locality is now a geotop. The crystals are not free standing but found covered by natrolite, but the crystals are easy to clean because of alteration of the rock. The magnetite specimens were abundant for a short time (1966 to 1973). Since that time collecting is almost impossible as the zone that was productive of the magnetite crystals is flooded. I think only a small number has been distributed, but one of the best magnetites in Germany. There are better specimens than the one pictured here
[Volker Betz 2010]


Magnetite
Germany
Bavaria, Lower Bavaria, Bavarian Forest, Zwiesel, Bodenmais, Silberberg Mine

Magnetite 5cm wide	© Rob Lavinsky

Magnetite
Germany
Rhineland-Palatinate, Eifel Mts, Mendig

1.37mm Magnetite xl on matrix	© Chinellato Matteo

Magnetite
Germany
Saxony, Glauchau, Callenberg

Magnetite 10cm wide	© Thomas Witzke

Magnetite 11.1cm wide	© Rob Lavinsky

Magnetite
Italy
Campania, Naples Province, Somma-Vesuvius Complex, Monte Somma, Ercolano, San Vito, San Vito quarry

1.22mm Magnetite xl on Diopside	© D. Preite - M.C.

1.23mm Magnetite xl with Diopside	© Chinellato Matteo

Magnetite
Italy
Lombardy, Sondrio Province, Malenco Valley

2.11mm group of Magnetite xls	© Chinellato Matteo

Magnetite 4.5cm wide	© Martins da Pedra

Magnetite
Italy
Lombardy, Sondrio Province, Malenco Valley, Lanterna Valley

Magnetite 10cm tall	© Maxminerals

Magnetite
Italy
Lombardy, Sondrio Province, Malenco Valley, Lanterna Valley, Campo Franscia, Franscia Mine

1.7 mm Magnetite cluster	© Chinellato Matteo

Magnetite on matrix 11 cm wide	© Maxminerals

Magnetite
Italy
Piedmont, Torino Province, Canavese District, Chiusella Valley, Traversella, Traversella Mine

Magnetite 6.2cm wide	© Rob Lavinsky

Magnetite ~8cm wide	© Chinellato Matteo

Magnetite
Italy
Piedmont, Torino Province, Canavese District, Léssolo, Cálea, Brosso Mine

Magnetite & Pyrite 16cm wide	©

Magnetite & Pyrite 6cm wide	© Rui Nunes 2008

Magnetite & Pyrite 12cm wide	© Carles Millan

Magnetite
Japan
Honshu Island, Chubu region, Nagano prefecture, Kuryu mine

Magnetite FOV 4.2cm	© R. Tanaka

Magnetite
Mexico
Chihuahua, Mun. de Aquiles Serdán, Santa Eulalia District

Magnetite on Quartz ~6cm tall	©

Magnetite
Mexico
Durango, Mun. de Durango, Cerro de los Remedios, Victoria de Durango, Cerro de Mercado Mine

Magnetite & Fluorapatite ~8cm wide	©

Magnetite 5cm wide	© Rob Lavinsky

The magnetites from this locality are not particularly outstanding, but when they occur with sharp yellow sometimes transparent apatite crystals, I must admit that I find I become more interested in them.


Magnetite
Morocco
Meknès-Tafilalet Region, Khénifra Province, High Atlas Mts, Tamazeght complex, Bou-Agrao Mt.

Magnetite 6.2cm wide	© Rob Lavinsky

Magnetite 6.3cm wide	© Rob Lavinsky

Magnetite
Morocco
Souss-Massa-Draâ Region, Ouarzazate Province, Tazenakht, Bou Azzer District, Bou Azzer

Magnetite 4cm wide	©

Magnetite
Mozambique

Magnetite 42cm wide	© Arliguie M

The only locality we have for this specimen is Mozambique, but the thing is huge and a deposit that produces things like this must produce other note worthy specimens. I hope someone can eventually tell us more about this locality and its specimens. The crystals on this specimen must be nearly as big as your fist and the thing must weigh well over 100 pounds.


Magnetite
Namibia
Erongo Region, Usakos and Omaruru Districts, Erongo Mountain

Magnetite 7.9cm wide	© Rob Lavinsky

Magnetite
Norway
Nordland, Hattfjelldal

Magnetite on matrix ~3cm wide	© AÖ 2010

Magnetite
Norway
Telemark, Porsgrunn, Mørje, Auen( Blue Pearl) Quarry

Magnetite 2,5cm	©

Hematite after Magnetite. 6,2 cm wide	© Ingulv Burvald

Auen is one of the many larvikitie quarries in this area. Larvikite is quarried as a dimension stone and is widely used as countertops and claddings. The commercial grade larvikite consist predominantly of blue or black schillerizing feldspar.
The larvikite was formed as igneous plutons during Permian (+/- 300mill years ago) rifting in the Oslo graben in southeastern Norway. These igneous plutons are host to numerous alkaline pegmatites carrying many rare minerals.

The magnetite at Auen was found in one of these pegmatites in 1996. The actual pegmatite was severly altered, with a clay mineral, albite covered microcline and magnetite as main minerals. Small zircon, molybdenite sheets and a yellow, transparent mineral was present as accessory minerals. Most of the magnetite was partly altered to hematite
The magnetite crystals reached almost 10 cm across and often had quite complex crystal shapes. The best specimen I found was a 15cm wide cabinet specimen consisting of three intergrown magnetite crystals. This specimen is now on loan to Agder Naturmuseum in Kristiansand. The magnetite was abundant in this material, and several truck loads of material were available just after the pegmatite was exposed, and magnetite could still be found in the quarry a few years after the initial exposure of material.
[Olav Revheim 2010]


Magnetite
Pakistan
North-West Frontier Province, Mansehra District, Naran-Kaghan Valley, Sapat Gali (Soppat; Suppat; Sumpat; Sumput)

Magnetite & Forsterite (peridot) 2cm tall	© TVM

Magnetite & Forsterite (peridot) 9cm wide	© Kuno Stoeckli

Magnetite & Forsterite (peridot) 3.8cm tall	© TVM

Magnetite & Forsterite (peridot) 3.3cm tall	© TVM

Magnetite & Forsterite (peridot) 6cm wide	© H. Obodda

Magnetite crystals growing with gem grade peridot crystals? Every collector would love to have one of these. But the association was not common and for every thousand peridot crystals there may have been one specimen with this association.


Magnetite
Russia
Far-Eastern Region, Primorskiy Kray, Olginsky District, Olga Bay

Magnetite ~9cm wide	©

Magnetite
Russia
Northern Region, Murmanskaja Oblast', Kola Peninsula, Kovdor Massif, Kovdor Mine

Magnetite 7.5cm wide	© Arliguie M

Magnetite
Russia
Northern Region, Murmanskaja Oblast', Kola Peninsula, Kovdor Massif, Zheleznyi Mine (Iron Mine)

Magnetite & Calcite 3.9cm tall	© Rob Lavinsky

Magnetite
b]Russia[/b]
Urals Region, Southern Urals, Chelyabinsk Oblast', Zlatoust, Nazyamskie Mts, Akhmatovskaya Kop' (Achmatovsk Mine)

Magnetite & Clinochlore 11cm wide	© Kevin Ward

Magnetite
South Africa
Northern Cape Province, Aggeneys

Magnetite & Chalcopyrite 7cm wide	© Rob Lavinsky

Magnetite
Spain
Extremadura, Badajoz, Burguillos del Cerro, Milucha Mine

Magnetite 7.5cm tall	© Angel Acedo

Magnetite 14cm wide	© Angel Acedo

Magnetite 8.5cm wide	© Angel Acedo

Magnetite
Sweden
Värmland, Filipstad, Nordmark (Nordmarksberg)

Magnetite & Calcite 10cm wide	© 2000 John H. Betts

Magnetite
Switzerland
Wallis (Valais), Binn Valley

Magnetite & Adularia 2.7cm wide	© Rob Lavinsky

Magnetite
Switzerland
Wallis (Valais), Binn Valley, Lercheltini (Lärcheltini) area

Magnetite 5cm wide	©

Magnetite ~7cm wide	©

Magnetite, xl on left ~4cm	©

Magnetite
USA
Arkansas, Hot Spring Co., Magnet Cove, Perovskite Hill

Magnetite 2.6cm tall	©

At one time magnet cove was famous for specimens of massive magnetite specimens that acted as natural magnets. They were rated in quality by the size of the nails they could pick up. The 16 penny grade would pick up 16 penny nails and the ten penny quality would pick up the larger ten penny nails (those that sold ten for a penny). The most highly sought after material was the spike grade material that would actually pick up a small railway spike.
[Rock Currier 2010]


Magnetite
USA
California, Fresno Co., Wright Mountain area, Christie Mine (Christi Mine; Christy Mine)

Magnetite & Dolomite 2.7cm tall	© Michael C. Roarke

Magnetite
USA
California, San Benito Co., Diablo Range, New Idria District

Magnetite on matrix 3.9cm wide	© Rob Lavinsky

Magnetite
USA
California, San Benito Co., Diablo Range, New Idria District, Santa Rita Mine (Union Carbide Nuclear; Santa Rita Asbestos Mine; Joe 5 pit; Joe 7-5 Mine)

Magnetite ~8cm wide	©

Magnetite
USA
Idaho, Lemhi Co., Spring Mountain District

Magnetite on Ludwigite 5.3cm wide	© JSS

Magnetite 4.3cm wide	© John Sobolewski

Magnetite 4.2cm tall	© JSS

Magnetite
USA
New Jersey, Hudson Co., Secaucus, Laurel Hill (Snake Hill; Penetentiary Quarry

Magnetite 4cm wide	© 2001 John H. Betts

Magnetite 8.8cm wide	© Frank A. Imbriacco III

At Laurel Hill, magnetite veins are common. Perfect specimens are not easy to come by, due to weathering and brittleness. Good specimens are obtained, when vein walls are composed of soft chlorite. Excellent splendent crystals were observed suspended as individuals and groups in the mountain leather variety of actinolite. Their color coal-black; crystallizing as octahedrons or penetrating (spinel) twins; up to 3 cm on an edge and associated with albite, sphalerite, pyrite, bornite, chalcopyrite, allanite, epidote, orthoclase, and quartz.
[Facciolla, N. (1981) Minerals of Laurel Hill, Secaucus, New Jersey, privately published book involving only this locality]


Magnetite
USA
New Jersey, Sussex Co., Franklin Mining District, Sterling Hill

Magnetite ~15cm wide	©

Magnetite
USA
New Mexico, Grant Co., Fierro, Hanover-Fierro District, Continental No. 2 Mine

Magnetite 2.3cm wide	© Rob Lavinsky

Magnetite
USA
New Mexico, Grant Co., Hanover-Fierro District, Republic Mine

Magnetite 5cm wide	© FL Murray

Magnetite
USA
New Mexico, Socorro Co., Jones District

Magnetite 5cm wide	© FL Murray

Magnetite
USA
New York, Essex Co., Port Henry

Magnetite 2.7cm wide	© Rob Lavinsky

Magnetite xls, label is ~5cm wide	© 2007 Peter Cristofono

Magnetite, big xl is ~12cm	©

Magnetite, xl on right is ~4cm	©

Magnetite ~5cm wide	©

These were at one time quite common among collectors in the north eastern part of the United States, but now are seldom seen. The bottom three images show not terminated crystals of magnetite, but rather parting forms that have been broken from massive twinned magnetite.


Magnetite
USA
New York, Putnam Co., Southeast Township, Brewster, Tilly Foster mine

Magnetite & Clinochlore ~12cm wide	©

Magnetite 3cm wide	© 2001 John H. Betts

The magnetite and clinochlore specimen pictured above is about as good as this association gets from this mine.


Magnetite
USA
New York, St Lawrence Co., Balmat-Edwards Zinc District, Balmat

Magnetite 5.8cm wide	© Rob Lavinsky

Magnetite 4.2cm wide	© Rob Lavinsky

Magnetite 7.2cm wide	© Rob Lavinsky

Magnetite 11.9cm wide	© Rob Lavinsky

Magnetite 9.2cm wide	© Rob Lavinsky

Magnetite 5.5cm wide	© Rob Lavinsky

The magnetite specimens from this mine have been around for a few years, but because of their brilliance and relatively cubic shape, they have a new standard of quality that other localities find difficult to match. The best from this locality are truly world class for the species.


Magnetite
USA
Pennsylvania, Berks Co., Morgantown, Grace Mine

Magnetite 5.5cm wide	© M.Heintzelman

Magnetite
USA
Pennsylvania, Chester Co., Warwick Township, St. Peters, French Creek Mines

Magnetite 6.8cm wide	© M.Heintzelman

There are better specimens of magnetite than the one pictured here and we will add one or more of them as soon as possible.


Magnetite
USA
Vermont, Windsor Co., Chester, Carlton Quarry (Carleton Quarry)

Magnetite ~7.5cm wide	©

Click here to view Best Minerals M, click here to view and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals M Thu, 11 Nov 2010 12:30:24 +0000 http://www.mindat.org/forum.php?read,79,151071,151071#msg-151071 http://www.mindat.org/forum.php?read,79,151071,151071#msg-151071 Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities? After each set of pictures there should be some descriptive text. If none appears it means that we need someone to tell us about the specimens from that locality and something about the geology of the occurrence.



Mirabilite
Na₂SO₄·10H₂O monoclinic

Mirabilite, Soda Lake, Carrizo Plain, San Luis Obispo Co., California, USA	©

Mirabilite is a water soluble evaporate mineral that forms in many salt lakes, often on a seasonal basis when the temperature and salt content of the brine is favorable to its formation. It is not a stable mineral under normal conditions and when removed from the brine will under most conditions quickly begin to loose its water and a crust of sodium carbonate (Thenardite) will start forming on its surface. If you quickly placed the specimens in an ice chest at about 0 degrees you could preserve this mineral intact. In the space of an hour or so the nice specimens you have collected will be just a pile of white Thenardite fragments.


Mirabilite
USA
California, San Luis Obispo Co., Carrizo Plain, Soda Lake

Mirabilite	©

Mirabilite	©

Mirabilite	©

Mirabilite	©

Mirabilite can be sometimes found at this locality when conditions are favorable for its growth in the mud just below the salt crust of this sometime dry lake. Collecting there is one of the dirtiest collecting experiences that field collectors will likely ever encounter. Use this link if you would like to read about collecting Mirabilite, Thenardite and other minerals at Soda Lake.
[Rock Currier 2009]



Click here to view Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals M Sun, 06 Sep 2009 01:45:25 +0000 http://www.mindat.org/forum.php?read,79,130896,149669#msg-149669 http://www.mindat.org/forum.php?read,79,130896,149669#msg-149669 Harjo Neutkens Best Minerals M Sun, 23 Aug 2009 18:03:23 +0000 http://www.mindat.org/forum.php?read,79,130896,148995#msg-148995 http://www.mindat.org/forum.php?read,79,130896,148995#msg-148995
just noticed a couple of small errors in the Wales section.

The Coed Ely entry is Mid Glamorgan, not Mis Glamorgan (other Mid Glamorgan entries are OK though).

The second Gelli Colliery picture is incorrectly dimensioned. It is shown as the FOV being 0.4cm, but it quite a bit bigger as the main crystal is itself 1.5cm

regards

ian]]> Ian Jones Best Minerals M Mon, 17 Aug 2009 13:44:57 +0000 http://www.mindat.org/forum.php?read,79,147007,147007#msg-147007 http://www.mindat.org/forum.php?read,79,147007,147007#msg-147007 Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities? After each set of pictures there should be some descriptive text. If none appears it means that we need someone to tell us about the specimens from that locality and something about the geology of the occurrence.


Muscovite

KAl₂[(OH)₂|AlSi₃O₁₀] Monoclinic

Minas Gerais, Brazil 6 cm	© Rob Lavinsky

Thin sheets of muscovite (showing it's property of flexibility) are commonly available, but good examples of crystals are not particularly common. Almost all of the specimens are from pegmatites, with Brazil being the most prolific. Also sometimes sheets of muscovite with various inclusions are sold.

The earliest use of muscovite was for jewelry. The first major use of muscovite was as a window pane for wood and coal burning stoves. Currently sheet mica is used as an electrical insulator and in electronic capacitors. It is also used as a "glitter" component in cosmetics.

Muscovite is found in all types of rocks. It occurs as a detrital component in sandstones and arkoses, is a major component in metamorphic rocks (mica schists), as an accessory mineral in granites and pegmatites and the variety sericite is common in many hydrothermal deposits. Most commercial production is from large books in pegmatites.


The most common forms are hexagonal crystals, but you can also get star twins, and aggregates forming balls. The largest known crystal of muscovite came from the Purdy mica mine in Ontario Canada. It measured at least 2.4m long and 1.5m in diameter.


Argentina
Catamarca, Papachacra

10 cm	© Rob Lavinsky

10 cm	© 2008 Steve Hardinger

Australia
Victoria, Lake Boga granite quarry

3 mm	© Judy Rowe

Austria
Salzburg, Krautgarten Mt.

10 cm	© Gerd Stefanik

Brazil
Espírito Santo, Mimoso do Sul Mine

12 cm	© Kuno Stoeckli

Brazil
Minas Gerais

5 cm	© Rob Lavinsky

5 cm	© Safaa Yu

5 cm	© Rob Lavinsky

8 cm	© Rob Lavinsky

3.5 cm	© Martins da Pedra

Fuchsite 6 cm	© JSS

Brazil
Minas Gerais, Divino das Laranjeiras

10 cm	© Rob Lavinsky

Brazil
Minas Gerais, Cigana claim

6 cm	© Martins da Pedra

Brazil
Minas Gerais, Zé Pinto prospect

9 cm	© Weinrich Minerals, Inc.

Brazil
Minas Gerais, Virgem da Lapa

4 cm	© CCURTO09

Canada
Ontario, Nipissing District

8 cm	© Russell G. Rizzo

Germany
Rhineland-Palatinate, Wannenköpfe

2 mm	© frank de wit

3 mm	© Fred Kruijen

Germany
Saxony, Neumark, Diabase quarries

var Astrolite 2.5 cm	© M. Adelt

Italy
Aosta Valley, Prabornaz Mine

var Alurgite 4 cm	© Paolo Grosso

Madagascar
Fianarantsoa Province,Malakialina pegmatites

4 cm	© ARLIGUIE M

Pakistan
Baltistan, Shengus

3 cm	© Christian Bracke

Portugal
Viseu District, Real quarry

3 cm	© Rui Nunes 2008

USA
California, Pack Rat Mine

12 cm	© Rob Lavinsky

USA
Maine, Mt. Apatite, Maine Feldspar Quarry

5 cm	© 2007 D. Levesque

USA
Maine, Lord Hill Quarry

5 cm	© 2007 Steve Bonney

USA
New Hampshire, Palermo No. 1 Mine

8 cm	© 2006 Peter Cristofono

USA
New Mexico, Harding Mine

3 cm	© 2010, JGW

9 cm	© Rob Lavinsky

USA
North Carolina, Rist Mine

8 cm	© Rob Lavinsky

USA
North Carolina, Lincoln Co.

Inclusions of garnet, rutile? 10 cm	© 2003 John H. Betts

USA
South Dakota, Diamond Mica Mine

8 cm	© Rob Lavinsky

Pseudomorphs of Muscovite

Bolivia
Potosí Department, Llallagua

after orthoclase 10 cm	© Rob Lavinsky

Japan
Kyoto Prefecture, Kameoka City

0.7 cm	© 2008, JGW

Variety sakura-ishi "cherry blossom stone" pseudomorphs after cordierite crystals.


USA
Arizona, Willow Spring Ranch

sericite after tourmaline 3 cm	© 2001 John H. Betts

USA
Maine, Noyes Mountain Quarry (Harvard Quarry)

sericite pseudomorph after tourmaline 2.5 cm	© 2001 John H. Betts

USA
New Hampshire, Atwood Mine

Pseudomorph after schorl 6 cm	© 2007 Peter Cristofono

Click here to view Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> David Von Bargen Best Minerals M Thu, 30 Jul 2009 16:21:36 +0000 http://www.mindat.org/forum.php?read,79,143977,143993#msg-143993 http://www.mindat.org/forum.php?read,79,143977,143993#msg-143993 Rock Currier Best Minerals M Sun, 05 Jul 2009 11:48:40 +0000 http://www.mindat.org/forum.php?read,79,143977,143977#msg-143977 http://www.mindat.org/forum.php?read,79,143977,143977#msg-143977 Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?




Meyerhofferite
Ca₂(H₃B₃O₇)₂· 4H₂O triclinic

1.Meyerhofferite after Inyoite, Mt. Blanco Mine, Death Valley, California ~11cm wide	©

Of the various kinds of Meyerhofferite specimens found thus far it would appear that the ones collectors most favor are the pseudomorphs after Inyoite (picture #1). I may be biased in my view because early in my youth I helped dig a wonderful pocket of these specimens in the Mt. Blanco mine in Death Valley. This mine also produced specimens of the other common type of Meyerhofferite, or primary Meyerhofferite as we call it. This is the cross hatched/reticulated almost honey comb variety that is exampled in picture 3 from Turkey below. I think that Turkey has produced the best of these specimens. Specimens containing crystals of this kind of Meyerhofferite up to 4 cm are said to be known.¹
1.Handbook of Mineralogy, Anthony, Bideaux, Bladh and Nichols Vol V. p450.
[Rock Currier 2009]


Meyerhofferite
Argentina
Salta, Sijes, Monte Azul deposit

2.Inyoite in/on Meyerhofferite, 17.7cm wide	© Rob Lavinsky

2.5.Meyerhofferite in Inyoite ~4.7cm wide	© Rob Lavinsky

All the specimens I have seen of Meyerhofferite I have seen from this locality are slightly altered crystals of Inyoite where enough of the Inyoite has been replaced by tiny white prismatic crystals of Meyerhofferite to render their usual transparent white/translucent nature mostly white. But in reality the bulk of the specimen is still Inyoite. Some of these specimens are very handsome and some people may feel that these are the most desirable kind of Meyerhofferite specimens to have. The one shown here, picture #2 is about as good as they get. Some very few specimens show both the unaltered and partially altered crystals on the same specimen. A very few others show transparent unaltered Inyoite with little sparkling whitish primary Meyerhofferite crystals growing in their interiors (picture 2.5) This deposit is is a little surface working where some heavy equipment has gone in and made some trenches and mined out some tons of material for processing into borate products. Several lots of Inyoite specimens were collected by various people, mostly visiting American geologists that worked for the company that was exploiting the deposits for industrial use. Probably the best material collected was done by Joe Siefke who was working for US Borax at the time. Probably less than 500 specimens total were collected before the pocket area was mined out. But at least a few specimens were saved from the mill and these will be with the collecting fraternity, probably for hundreds of years, long after this little barren patch of the Altiplano is long forgotten.
[Rock Currier 2009]


Meyerhofferite
Turkey
Marmara Region, Balikesir Province, Bigadiç

3.Meyerhofferite, 12cm wide	© Marco Barsanti

4.Meyerhofferite, 9.5cm wide	© jm.CLAUDE

It would appear that many wonderful borate specimens have been produced at Bigadiç, one of the oldest known Turkish borate localities. They certainly appear to have produced the best specimens of the crosshatched/reticulated varieties. We need someone to tell us about the Meyerhofferite specimens from this locality.


Meyerhofferite
USA
California, Inyo Co., Death Valley, Furnace Creek District, Black Mts, Mount Blanco mine

5.Meyerhofferite after Inyoite ~12cm wide	©

6.Meyerhofferite after Inyoite ~7cm wide	©

7.Meyerhofferite after Inyoite ~6cm wide	©

8.Meyerhofferite ~4cm wide	©

9.Meyerhofferite ~3cm wide	© John Sobolewski

10Meyerhofferite FOV 15mm	© 2008 Jesse Crawford

11.Meyerhofferite, 5.3cm wide	© Rob Lavinsky

12.Meyerhofferite ~4cm wide	©

This locality is barely a mine, probably more accurately it should be called a prospect. It has a short little tunnel, less than 100 feet long with a couple of little crosscuts that branch to the right. It was in these little cross cuts, probably not more than 10 feet long that produced the wonderful specimens of Meyerhofferite pseudomorphs after Inyoite as well as a few specimens of the reticulated variety. The pockets of pseudomorphs that were encountered, probably no more than two or three pockets of less than a meter in extent produced all of the known specimens of this type. Probably less than 500 specimens all total, though one of them, a fine specimens measured perhaps ~50cm in diameter. The specimens from the tops of the pocket showed specimens of chalk white nature, pictures #5, 6, & 7, while those from the bottom had a more sparkling nature, picture #1 due to the present of tiny crystals well crystallized Meyerhofferite growing on the pseudomorphed crystals. Perhaps the largest of the pseudomorphed Inyoite crystals measured ~12 cm across.
[Rock Currier 2009]



Click here to view Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals M Sun, 05 Jul 2009 03:58:17 +0000 http://www.mindat.org/forum.php?read,79,141514,141514#msg-141514 http://www.mindat.org/forum.php?read,79,141514,141514#msg-141514 Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.



I missed this topic last year but what I can say it is when I read
"...attached a thin copper wire to natural malachite bearing matrix.
They were next put into a copper rich solution and then by administering some form of electrostatic charge the malachite crystalized around the wire to form a stalagtite..."
I never heard about that, where are the scientific reports? I would love to read them.
Because for the 10 or 12 years ago fakes, I can tell you it was much more simple, it was crushed roughy malachite + glue on real broken stalactites or on pieces of wood" and that's it!
They had not the technic to do that (and is it possible to do that?) and it was more simple.
Now for the piece of wire inside, I confirmed I found some....but it is quite funny to read some scientific explanations of growing around and electrostatic... they just used pieces of wire to put in the hole of the stalactites broken!
When a stalactite is broken you have the hole inside and putting a wire inside just help to maintain it when you glue it.Only for that!
Now I'm maybe wrong about some scientific explanations but I just want to read the reports, I never heard about that.
So please for my knowledge, if anybody has a scientific report confirming 100% this technic, forward it to me.
Because a rumor is easy and destroying.
When I know how hard and dangerous sometime it is to travel to the sources.
I gave to Jolyon a small note to publish about my own small experience of traveller to Congo and some easy way to try to determinate if a stalactite is fake or not.
I have not the divine truth but I just try to bring my own experience to this topic.


In the past it was easy to go on the field in Congo, the mines were not working and the guys had easy access. Now for the last 5/6 years new private owners are mining and the access is closed.It will be difficult to have some photos but I will ask my guys if they can.And it is also maybe one year they didn't find any really good ones unfortunatly.
About the photos published, lets play the quizz but again it is a feeling, I can't be sure 100% on photos, I would say:
* 104633 from Debbie: should be real but maybe repaired with glue+malachite crushed on the 1/3 from the base
* Lawrie piece: can be fake
Debbie links:
*132897:no photo
*117571: real
*140554: should be real
*112: real
*89207: no photo
*97312: can be fake
Again, if you have any doubt, me I put the piece in acetone.

About the fake stalactites, there is not one locality especially because they could use a matrix from The Star of Congo Mine (SCM) and a broken stalactite from Kasompi....
But if you want a joke, one of the guys who made the 1st ones was called Baudouin and now when they show me a fake one (after yelling and explaining that they can loose more than they win...but they need money to feed the family...), I just tell them "I don't want your baudouinite....".
Baudouinite is the "official" name of the fake malachites on the local market of Lubumbashi....

In the last 2-3 years the Kasompi Mine (KM) has been the one producing most the stalactites on the market (I speak about real ones) but the quality was not as good as the ones from SCM, most of them were darker.
In the past, several mines in the Congo produced some fine stalactites: Lupoto, Luishia (fantastic velvet ones), Lukuni....

But the SCM has produced most of the best malachites, botryoidal or stalactites, in quality and in quantity.
This mine is fantastic for the diversity of shapes, colors (from light to dark), associations with chrysocollas.
Unfortunatly we don't see anymore significant pieces for the last 5-6 years because a private company is mining at the SCM and the security on the pit doesn't allow the guys to go there.

You can see on the market many pieces with a wrong label "Mashamba west Mine" (MWM) when it comes from the SCM.
The MWM has been famous in the past for its primary malachites producing some real crystal up to 6-8 cm, some great "flowers" of malachites, sometime combined to red gemmi cuprites, light green acicular malachite, orange barites...and what almost nobody knows, in 90-91's my father brought a 20 cm doble terminated crystal of azurites but completly oxydated from MWM.
Few weeks later began the civil war and since that time the mine is floatted!! But there is a pocket of azurites still waiting under a green lake of cooper water....
All the Kolwezy are has also produced the very quality of malachite rough for the carving and the jewellery.

Hope these informations from my own experience in the Congo will help you.

Christophe Gobin



Click here to view Best Minerals M and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.]]> Rock Currier Best Minerals M Sun, 14 Jun 2009 05:11:45 +0000 http://www.mindat.org/forum.php?read,79,130896,140352#msg-140352 http://www.mindat.org/forum.php?read,79,130896,140352#msg-140352 I'll add it right away!

I wish it were in my collection, but it is not. Casey came into my warehouse shortly after he had dug the specimens and showed me a box full of them. Many had not yet been trimmed or cleaned. He knows I collect micros so I picked up one of the larger specimens, turned it upside down and shook it and when nothing fell out, I demanded, where are my micros and shook it some more. He eventually did get me some very nice micros. He didn't have all that many of them and I knew he was going to have to get big money for the good ones, so I decided to settle for some micros, but it is nice to see a bunch of a nice new find like that.]]> Harjo Neutkens Best Minerals M Wed, 03 Jun 2009 18:51:06 +0000 http://www.mindat.org/forum.php?read,79,130896,140199#msg-140199 http://www.mindat.org/forum.php?read,79,130896,140199#msg-140199
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I also uploaded 8 images of the collecting site in the mine where the millerite was collected.]]> Rock Currier Best Minerals M Tue, 02 Jun 2009 07:58:36 +0000 http://www.mindat.org/forum.php?read,79,130896,140019#msg-140019 http://www.mindat.org/forum.php?read,79,130896,140019#msg-140019 Harjo Neutkens Best Minerals M Sun, 31 May 2009 19:55:03 +0000 http://www.mindat.org/forum.php?read,79,130896,139450#msg-139450 http://www.mindat.org/forum.php?read,79,130896,139450#msg-139450
The Colliery produced high quality steam coal which was greatly in demand notably by Cunard Steamlines. Deep Navigation became the sole source of the coal used for the record-breaking "Blue Ribband" trans-Atlantic crossings of both the SS. Mauretania and the SS Lusitania.]]> Ian Jones Best Minerals M Wed, 27 May 2009 09:51:34 +0000 http://www.mindat.org/forum.php?read,79,130896,139449#msg-139449 http://www.mindat.org/forum.php?read,79,130896,139449#msg-139449
just noticed that i missed tons off the output figure8-)]]> Ian Jones Best Minerals M Wed, 27 May 2009 09:42:17 +0000